In an attempt to accurately measure DNA content with simultaneous preservation of cell surface markers, we have utilized gentle ethanol treatment techniques, which permeablize cells with minimal loss of surface antigen expression and antibody-antigen association. For some cell types, the presence of apoptotic cells based on reduced DNA content can also be detected. One such technique employs the addition of ethanol to cells previously resuspended in high concentrations of fetal bovine serum... - [Read Simultaneous Analysis of DNA Content and Surface Immunophenotype Protocol]
Describes how FACSort can be used to enrich for transfected mouse cells expressing high levels of the human thrombin receptor. The sorted fraction can then be cultured in vivo and reanalyzed 12 days later to show that it remains enriched for thrombin receptor-expressing cells. - [Read Sorting Transfected Cells Based on Gene Expression, Followed by Culture in Vivo]
Protocol describes a split luciferase complementation assay that can be used to repetitively and noninvasively study the interaction of proteins in small living animals. After the expression of the appropriate vectors has been checked in cell culture in vivo, studies can be performed either by implanting transiently transfected cells for short-term analysis (maximum of 7 days), or with tumor models grown from tumor cells stably expressing the complete reporter system. - [Read Split Luciferase Complementation Assay for Studying Interaction of Proteins X and Y in Living Mice]
Sterile technique is one of the most important steps in insuring consistent results when employing recombinant DNA and protein expression techniques. Dr. Chazin Lab, Center for Structural Biology, Vanderbilt Univ. - [Read Sterile Technique for DNA and Protein Expression]
Protocol describes a target selective S. aureus whole cell assay that combines agar-diffusion and protein over expression techniques. This agar based two-plate differential sensitivity assay was used to help confirm the newly discovered antibiotic platensimycin inhibited bacterial growth by specifically targeting the essential FASII enzyme FabF6. - [Read Target Specific Whole Cell Assay for Antibacterial Drug Discovery Protocol]
The protocol is one example of differential gene expression analysis of cells obtained from microdissected tissue. Includes: Microdissection and RNA Isolation; Reverse Transcription; PCR; P.A.G.E.; Sequencing of Differentially Expressed Bands. - [Read Targeted Differential Display Protocol]
Stably transfected cells, generated in the first two stages of the procedure, are induced for expression of the target gene. After harvesting and lysis, the lysates are analyzed by SDS-PAGE and immunoblotting. - [Read Tetracycline as Regulator of Inducible Gene Expression III]
Protocol uses an autoregulatory system in which the transcriptional trans-activator tTA drives its own expression and that of a target gene. The first stage of the procedure describes how to generate stable lines of NIH-3T3 cells that express either tTA alone or tTA and the tetracycline-regulated target gene. - [Read Tetracycline as Regulator of Inducible Gene Expression Protocol]
This stage of the procedure describes the transfection with target genes of cell lines already expressing inducible tTA. In this example, the target genes are transfected on a plasmid that carries puromycin resistance as a selectable marker. - [Read Tetracycline as Regulator of Inducible Gene Expression Protocol II]
This protocol fixes and prepares embryos for in situ hybridization to visualize transcript expression patterns. It is a modification of the method developed by Tautz and Pfeifle for whole-mount in situ analysis of embryos. Use of the standard hybridization protocol on RNAi-treated embryos results in high background staining, which makes visualization of transcript expression patterns practically impossible. The following modifications eliminate this problem and allow visualization of transcript. - [Read Transcript In Situ Hybridization of Whole-Mount Embryos for Phenotype Analysis of RNAi-Treated]
DEAE-dextran is generally used to obtain a burst of transient expression of cloned genes after transfection of mammalian cells. Many variants of the technique have been described, all of which seek to maximize the uptake of DNA and to minimize the cytotoxic effects of DEAE-dextran. In this protocol cells are exposed briefly to a high concentration of DEAE-dextran-DNA and then to chloroquine diphosphate, which is a facilitator of transfection. - [Read Transfection Mediated by DEAE-Dextran: High-efficiency Method Protocol]
This procedure, which uses a root transformation protocol, provides a rapid method for assessing gene expression in Arabidopsis roots. It is useful for testing promoter:reporter gene constructs, for expressing genes, the overexpression of which is lethal in whole plants, and for transforming the roots of plants that are recalcitrant to conventional transformation techniques. The protocol has been used successfully with Ws, No-0, and RLD ecotypes. - [Read Transgene Expression in Regenerated Roots]
The study of transient gene expression provides a useful complement to the study of stably transformed plants. Transient assays offer a quick method of testing the effects of genes, using either phenotypic, molecular, or biochemical readouts. Transient assays based on Agrobacterium-mediated transformation of leaf explants have been described for other plant species, but it is not known how well these assays work in Arabidopsis. - [Read Transient Expression in Protoplasts]
Transient transfection into mammalian cells is a convenient way to over express and obtain protein expression. Protocol includes: Culture conditions; Transfection of experimental cells; Preparation of Mammalian Cell Lysate for Luciferase assay. - [Read Transient Transfection and Luciferase assay]
Transient transfection into mammalian cells is a convenient way to over express and obtain protein expression. Protocol includes: Culture conditions; Transfection of experimental cells; Preparation of Mammalian Cell Lysate for Luciferase assay. - [Read Transient Transfection and Luciferase Assay Protocol]
Procedure describes how it denatures most of the modification and degradation proteins immediately giving the most accurate read out of the true levels of protein at the time of harvest. However, in cases where detection is a problem, a limited purification (e.g. isolation of nuclear extract for the detection of transcription factors) might be required to allow analysis. - [Read Western Blot Analysis of Endogenous Gene Expression Protocol]
This protocol describes nuclear and cytoplasmic fractionation of tissue culture cells and a method for Western blot detection of proteins using the Odyssey Infrared Imaging System. This protocol was used to detect expression of the "small" Tap protein in 293T, HeLa and COS cells. The Odyssey system has several advantages over the more widely used chemiluminescent detection methods. - [Read Western Blot Analysis of Sub-Cellular Fractionated Samples Using the Odyssey Infrared Imaging System]
DNA microarrays are an ordered arrangement of DNA molecules complementary to genes of interest that are "spotted" by robotic equipment onto a glass slide substrate. The expression of genes in cells can be monitored with microarrays by preparing cDNA from the mRNA of cells of interest and measuring the hybridization to the microarray. This protocol describes the labeling of genomic DNA for use as a probe for hybridization to the cDNA spotted on the array.
This Microarray Protocol Preparation of Fluorescent DNA Probes from Human mRNA protocol describes the production of probes labeled with the fluorescent dyes, Cy3 and Cy5, following the synthesis of cDNA from human mRNA and the hybridization of the probes to DNA microarrays.
Paraffin Embedding Protocol for molecular profiling. This Paraffin Embedding Protocol describes the processing of the tissues into sections following ethanol fixation. Molecular profiling (MP) is a technique that is used to visualize the global patterns of RNA expression or protein expression in various cell types and disease processes.
The protocol gives general considerations for the design of targeting vectors for transgenic mice. The protocol shares tips in the design of knock-out and knock-in vectors and some of their strategies for producing homologously recombined embryonic stem cells.